Parallelism, Angle of

The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Parallelism, Angle of

 

in Lobachevskian geometry, the angle of parallelism at a point A with respect to a line a is the acute angle formed by a line through A parallel to a and a perpendicular from A to a.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.